Folding scaffold jack or trestle



Sept. 20, 1938. Q'ENGMAN V2,130,456

FOLDING SCAFFOLD JACK OR TRESTLE Filed June 4, 1957 Patented Sept. 20, 1938 narran srarss FATENT FFEQE 1 Claim.

This invention relates to scafolds, the primary object of the invention being to provide a scaffold comprising extension jacks including leg members and a beam connecting the leg members, means being provided for removably connecting the beam to the leg members in. such a way that the scaifold may be readily and easily set up or dismantled, due consideration being given to the strength and durability of the scaffold.

Another object of the invention is to provide a scaffold including trestles which may be used either as a scaffold or support to be positioned against a wall or building, or used as a support in places Where a wall or building is not available as a support against which the jack of the scaffold may lean.

.With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinaiter described and claimed, it being understood that changes in the precise embodiment of the invention herein described, may be made within the scope of what is claimed, without departing from the spirit of the inven tion.

Referring to the drawing:

Figure 1 is an elevational view illustrating a scaffold constructed in accordance with the invention, and showing the scaffold as leaning against a building or wall.

Fig. 2 is a sectional view taken online 2-2 of Figure l.

Figure 3 is a sectional view taken on line 3-3 of Figure 1.

Figure l is a sectional View taken on line lof Figure 2.

leg sections 6, passing through the straps 'l se.

cured to the main leg section 5, near the lower ends thereof. A plurality of spaced openings 8 are formed in the main leg sections 5, and are designed to accommodate the bolts 9 which extend through the adjacent leg sections, and by placing the bolts 9 in various openings, the lengths of the leg sections may be adjusted to meet various requirements.

The upper ends of the main leg sections 5 are connected by the stirrups EG which include pivotally connected sections, connected by means of the bolt il. Spurs l2 extend inwardly from the strrups, and are designed to bite into the beam which is used in connection with the supporting legs of they scaffold, and which in the present showing is indicated by the reference character i3. Grooves l@ are formed in the beam I3, and provide pockets for the stirrups l5, as clearly shown in Figure 1 of the drawing. Thus it will be seen that when a beam is positioned within a stirrup, and the leg members of the scaffold are spread apart, the spurs will bite into the beam, securing the beam against movement within the stirrup. The sections of the stirrup are secured to the main leg sections 5, by means of the bolt l5, the upper ends of the stirrup sections being turned outwardly providing iianges i6 that rest on the upper ends of the main leg sections 5, as clearly shown by Figure 2 of the drawing.

The construction of the stirrups is such as to present parallel flanges I'l that t within the grooves M, which are of widths to accommodate the flanges.

Plates indicated by the reference character i3, are secured to the inner surfaces of the main leg sections 5, by means of the screws i9, the plates being provided with openings registering with openings in the main leg sections. 5, for the reception of the eye bolts 25, the threaded ends of the eye bolts 20 being positioned in the nuts 2i which are embedded in the main leg sections 5, at the inner ends ofthe openings receiving the eye bolts 2li.

These eye bolts also provide means for connecting the outer ends of the brace bars 22 to the leg members, the opposite ends of the brace bars 22 being connected by means of the bolt 23 which is supplied with a wing nut 24, so that the brace bars may be readily and easily disconnected When the leg members of the scaffold are in their folded positions, the eye bolts 26 will overlie each other, to the end that one of the rightangled end portions 26 of the rod 2 may be positioned in the registering eyes of the eye bolts, securing the leg members in their folded position, as shown by Figure '7 of the drawing.

Near the lower ends of the main leg sections 5 are eye bolts 28 which are of constructions similar to the eye bolts 20, the eye bolts 28 adapted to receive the bolts 29 placed at the free ends of the pivotally connected brace arms 32. Thus it will be seen that when the main leg sections 5 have been spread apart, the brace arms 30 will maintain the main leg members in such spaced position.

In the use of the device or in the formation of a scaffold, it will of course be understood that two or more of these jacks are employed, and the necessary scaffold boarding is positioned thereon.

In the present showing, I have illustrated the jack as used in connection with a vertical Wall, wherein the beam I3 thereof engages the wall.

Should it be desired to use the jack wherein a supporting wall such as indicated in Figure 1 of the drawing, is not available, it will of course be understood that leg members may be connected to the beam I3, at the opposite end thereof, providing a complete support for the usual scaffold boards.

Having thus described the invention, what is claimed is:

A folding scaffold jack comprising a pair of leg members, a stirrup connecting the upper ends of the leg members, said stirrup embodying members having inwardly extended flanges formed along their longitudinal edges, extensions formed at the lower ends of the anges, a bolt extending through the extensions pivotally connecting the sections of the stirrup, said flanges adapted to bite into a scaiiold bar positioned in the stirrup when pressure is directed thereto, and outwardly extended anges at the upper ends of the stirrup adapted to rest on the upper ends of the leg members, supporting the weight of the scaffold.

OLQF ENGMAN. 

